Interrupter mechanism for ignition-dynamos.



C. T. MASON.

INTERRUPTER MECHANISM FOR IGNITION DYNAMOS.

APPLICATION FILED JUNE 30,1915.

'1 ,21 6,1 5 1. Patented Feb. 13,1917.

2 SHEETSSHEET I.

C. T. MASON.

INTERRUPTER MECHANISM FOR IGNITION DYNAMOS.

' APPLICATION {11.50 JUNE 30, 1915.

1,216,151. Patented Feb.13,1917.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

CHARLES THOMAS MASON, OF, SUMTER, SOUTH CAROLINA, ASSIGNOR, BY MESNEASSIGNMENTS, TO SPLI'IDORF ELECTRICAL COMPANY, OF NEWARK, NEW JERSEY,

A CORPORATION or NEW JERSEY.

INTEBBUPTEB MECHANISM FOR IGNITION-DYNAMICS.

Specification of Letters Patent. I

Patented Feb. 13, 1917.

Application filed June 30, 1915. Serial No. 37,130.

To all whom it may concern:

Be it known that I, CHARLES THOMAS Masozv, a citizen of the UnitedStates, residing at Sumter, in the county of Sumter and State of SouthCarolina, have invented certain new and useful Improvements inInterjec't the improvement thereof in such manner as to increase theefiiciency and atthe same time lengthen the life of the interruptercontacts and their operating parts, to obviate certain diflicultieswhich have heretofore arisen from the high speed of operation of some ofthese parts, and to reduce sparking at the contacts.

' The method commonly employed in ignition systems of the high tensionjump spark type has been to provide a pair of contacts in theinterrupter, with a cam opening or closing the same at the proper pointon the E. M. F. wave in the generating coil,so as to render thesecondary discharge circuit operative for an instant. F or ordinaryspeeds this method has been found satisfactory, but when the speed ofthe magneto rotor is increased beyond the critical point, or when thecam is given several raised operating surfaces so as to produce severaloperations of the contact lever for each revolution of the rotor, thendifficulty is experienced. In my prior application filed June 19, 1915,Serial N 0. 35,155, I have described and claimed a system, method andapparatus, whereby four current changes are produced in the generatingcoil per revolution of the rotor, and the cam which is driven with therotor has four raised operating surfaces. If this rotor makes 3000rev0lutions per minute, the interrupter contacts per second. While it istrue that the contacts must remain open for an appreciable length oftime in order to permit a proper spark and the ignition of a charge ofgas thereby, yet owing to the rapidity with which the lever movementsfollow, each other, its vibration is practically continuous, and theonly effect of obstructing or damping its free vibration by the camsurfaces is to produce additional wear and cut down the actual time oftravel, thereby increasing the actual speed of travel for each movement.

Under the conditions stated, it cannot be expected that the contactlevers and contacts will be either highly eflici'ent or long lived. Bydint of care in the selection of the materials and in the craftsmanshipemployed, the parts requisite for practising this method can be madefairly satisfactory for a short time, but with certainty of breakage tofollow, however.

I attain my objects heretofore stated by multiplying the number ofcontact levers and providing a corresponding number of cams so arrangedthat the contact levers will make or break the circuit successively, themakes or breaks alternating, so that I may atvonce divide the number ofelevated surfaces required on the cam by the number of cams and leversemployed. I shall specifically describe herein a structure in which twolevers, two pairs of contacts, and two cams are employed, each camhaving two elevated surfaces and the two cams being arranged with theirraised surfaces in quadrature, while the anvil contacts of the two pairsare connected. Obviously, each of the levers by this arrangement needonly vibrate half as rapidly as one would be forced to do. Similarly, ifI should increase the number of cams and levers to three or four, thespeed of vibration would be reduced to one-third or one-fourth, and soon. I am well aware that it is not new to provide a magneto interrupterwith more than one pair of contacts, or with more than one contactlever. I am not aware, however, of any case in which a plurality ofcontacts or of levers are used for my purpose, and I shall thereforeclaim the same, as well as the system employing them, and their methodotuse, broadly as well as specifically. My invention is illustrated inthe accord panying drawings in which- Figure l is a front view of theintcrrupter embodying the invention.

ill

Fig. 2 is a diagram of the preferred at: rangement showing the circuits,and interrupter parts in enaggerated perspective.

Fig. 3 is a diagram of another arrangement; 1

is a side view partly in section of a dynamo with my improvedinterrupter at tached thereto.

' While this inventionmaybe iJsed-toad-,

vantage with any type of magneto in such a system and for the purposeherein described,

it is particularly designed for use with the type of ignition dynamodescribed in my prior Patents No. 1,081,? (SO dated December 16,1913,No. 1,105,361, dated July 28, 191i,

' the prongs of the Us bridging each other and No. 1,126,676 datedJanuary '26, 1915, a the same being fully developed in my priorapplication Serial No. 35,155,-'- filed June -l9, 1915, in which I havedescribed a rotor with two U-shaped oppositely polarized elements,

from opposite directions and alternating in position, each opposite pairbeing angularly displaced by 90 so that the four-prongs are inquadrature. The fixed or armature poles in tliisarrangement areseparated byan angular distance equal to the distance between thepolesof a'--pair'a-nd the rotor, and when this four-pronged rotor isturned with relation to fixed poles,"there will be fourreversals ofpolarityand therefore four E; M. F. and current waves produced in thegenerating coil whose magnetic core structure terminates in said fixedpoles.

.Fig. l shows partly in section the generator describedin my saidpriorapplication,

with the "interrupter I mounted upon it.

The structure of this'interrupter is better shown, however, in Fig. 1, 2and 3. ()n the based are pivoted the' two contact levers a? and, whicharerespectively held against their anvils a? and i" by the springs i and5 Each levercarries a bumper it or i and the two levers-i and i aswellas the twb contacts 2" and v7, m'ay conveniently be connectedtogether, the two contacts being insulated, however, from the base inthe same manner that the single anvil contact of my prior cases has beeninsulated. The connection of the levers and anvils is very well coil isconnected.

indicated in Fig. 2, both levers being shown as grounded or connectedmetallically to the frame of the machine", while both anvils, be-

ing insulated, are connected to thacommon, end of the primary conductorto which one With this arrangement, that is to say, with the levercontacts and the anvil condrawings.

ars er tacts in parallel, the cams are termed as shown in Fig 1 tomaintain both pairs of contacts open during a brief portion of eachquarter revolution, and to maintain one of the contacts open while theother is closed I during another portion. of each quarter revolution,the closing and opening of each con-- tact" alternating, and each beingrepeated twice in a complete revolution. The two employed are marked iand it, the up per one i being shown in full lines and the contour ofthe latter one being indicated thereon in dotted lines. It should beparticularly noted that the elevated operating surfaces @2 and z'toverlap at their ends.

This means that one or the other of the pairs of contacts controlled bythe levers i and i either the bumper v1 or the bumper i into a followingdepression. At the end of this depressions aid bumper will rise againand for a brief period both pairs of contacts are again opened,whereupon the other bumper drop into a depression and so on. 'Durmg eachdepression, the corresponding pair of contacts is closed for a portionof a fourth -revolution of thecarn, so that wehave four short breaks perrevolution, and by properly adjusting the cams on the rotor shaft, or ifthese are fixed, then by properly adjusting the interrupter casing andcontact levers around the cams, we can time the four makes so that theywill comeiprecisely at the correct points onthe four E. M. F. or currentwaves produced by the generating coil for each revolution of the rotorand its shaft. This rotor shaft is indicated by g in the lnFig. 3 l haveshown a modified circuit arrangement, in which the anvil contacts areconnected as before, but are includedv 1n series with the contact leversi and 5 one of which is connected to ground and the other throughconductor 0 to the coil 9 which on its other side is grounded. In

this modification the contact levers must be insulated from each other,while the anvils are connectedtogether, but insulated from both levers.Also, the cams are arranged without any overlap, so that one of theleefact, the best results in this form require the cutaway portions ofthe two cams to overlapfso; that both levers will be closed during apart of each fourth revolution. The effect produced by closing bothlevers is supposed to be to shunt or disable the primary'coil, the shuntbeing broken when either lever is, raised through its anvil. As

vers will always be closed. As a matter of I each lever is raised by oneface of its cam twice in a revolution, there are four breaks in thecontrol circuit or shunt in a revolution and again by adjusting thelevers and contacts with respect to the cams, we may time theinterruptions so that they will come precisely at the proper points onthe M. F. and current waves.

I wish it clearly understood that a number of changes and modificationsin matters of detail can be made in this device without departing fromthe spirit of my invention, and I contemplate as my own all suchnon-essential changes and modifications as fairly fall within the scopeof the appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent 1s-.-

l. The method of controlling discharges at a relatively high frequencyin a current generating coil, consisting in effecting a. joint controlthrough a plurality of pairs of contacts operating individually andindependently to produce a discharge, said contacts being operated insuccession whereby the time interval between any two control operationsof a single pair of contacts is equal to the time interval betweendischarges in the generating coil multiplied by the number of pairs ofcontacts.

2. The method of controlling discharges at a relatively high frequencyin a current generating coil, consisting in effecting a joint controlthrough a plurality of pairs of contacts arranged in multiple, operatingsaid contacts in succession, and closing and opening a pair of contactswhile the other contacts are open.

3. In an ignition system, a current generating coil, and devices forcausing discharges at a relatively high frequency in the currentgenerating coil, said devices including a plurality of pairs ofcontacts, and means for operating said contacts in succession, saidmeans being timed so as to open and close a pair of contacts while theother contacts are open whereby each pair of contacts individually andindependently control the discharge.

4. In an ignition system. a dynamo having a generating coil. a rotoradapted to produce a determinate number of E. M. F. changes in the coilfor each rotation thereof, a discharge circuit connected to said coil,and a governing device consisting of an interrupter having a pluralityof pairs of contacts, and means for operating said pairs of contacts insuccession and for closing and opening a pair of contacts while theother contacts are open whereby each pair of contacts individually andindependently controls the discharge.

5. In an ignition system, a dynamo having a generating coil and a rotoradapted to produce a determinate number of E. M. F. changes in the coilfor each rotation, a discharge circuit connected to said coil, and agoverning device consisting of an interrupter having a plurality ofpairs of con tacts, each pair of'contacts adapted to completely controlthe discharge and the two pairs acting in alternation, and means drivenwith the rotor to actuate said pairs of contacts alternately.

6. In an ignition system, a dynamo having a generating coil and a rotoradapted to to produce a determinate number of E. M. F.-

changes in said coil for each revolution, a discharge circuit connectedto said 0011, an interrupter having a plurality of pairs of contactsconnected in series in a control circuit rendering the discharge circuitnormally inoperative, and a corresponding plurality of cams drivensynchronously with the rotor, adapted to open and close said pairs ofcontacts in alternation, the number of actuating surfaces on each cambeing such thatthe total number of operations of the associated pair ofcontacts in a given period of time will be equal to the total number ofE. M. F. and current changes in the generating coil, divided by thenumber of pairs of contacts.

8. In an ignition system, a dynamo having a primary and a secondarygenerating winding, a field,and a rotor adapted to produce a determinatenumber of E. M. F. and current changes in said windings for eachrevolution, the two windings being connected to a common conductor atone end,

the other end of the primary being grounded and the other end of thesecondary connected to a discharge circuit, and an interruptercomprising a plurality of pairs of contacts connected to said commonconductor, and a corresponding plurality of cams set in alternation anddrlven with the rotor, to actuate said pairs of contacts alternately andat each actuation to produce a discharge through the secondary windinginto the discharge circuit.

9. In an ignition dynamo, an interrupter comprising a plurality of camswith their actuating surfaces angularly displacedso as to comealternately into working position, a

plurality of contact levers, one for each cam,

' a movable contact on the end of each lever,

and a plurality of fixed or anvil contacts, one for each movablecontact, said contacts and cams being adjusted so that whenone' pair ofcontacts is opened the others Wlll be closed and vice versa, and eachpair when actuated will produce one complete interruptero operation.

10. ln an ignition dynamo, a generating coil, means for producing E. M.F. and curtotal number of changes in the generating naiaaai goil'divided by the number of contact memera l J j i 11. an ignition dynamo,an'interru ter comprising a plurality ofcontact mem ers arranged foralternate control of the dynamo circuit, and means for driving saidmembers collectively at a speed such that the number of indiyidualactions of each contact member for a given time will be less than thetotal number of current changes 1n the dy:

name in the same time, 1 a

In testimony whereof l hereunto afix my signature in the presence of twoWltIlQSSBS;

Q LES THUMAS ASON. Witnesses: t I

EDNA llannn'

